“I don't think they could dislodge the Armenian forces from the high ground. I think that's extremely difficult,” Bryza said.

Over the past decade, Azerbaijan has spent billions of dollars of its oil revenues on a military build-up which it hopes will eventually end Armenian control of Karabakh. President Ilham Aliyev and other Azerbaijani officials regularly threaten to forcibly win back the disputed territory. Aliyev has repeatedly claimed that his armed forces are already strong enough to accomplish that.

Armenian leaders dismiss and at the same time denounce such threatens. Analysts in and outside the region likewise question the Azerbaijani army’s ability to defeat the Armenians.

“I think it would be a month or two, that is the amount of time our armed forces could fight for,” Yusif Agayev, an Azeri military expert and veteran of the war, told Reuters. “If it drags on longer then it will become a war that society will have to participate in, not just the army,” he said. “I don't think the society of my country is ready for war.”

Bryza, who currently runs a defense think-tank in Estonia, was closely involved in international efforts to end the Karabakh conflict in 2005-2009 in his capacity as deputy assistant secretary of state and the U.S. co-chair of the OSCE Minsk Group. He went on to serve as U.S. ambassador to Azerbaijan in 2011.

Bryza was appointed as ambassador on a temporary basis after President Barack Obama failed to secure the U.S. Senate’s approval of his candidacy for the post in 2010. Some Armenian-American lobbying groups accused the career diplomat of having a pro-Azerbaijani bias and questionable ties to Azerbaijani officials. Bryza strongly denied the accusations.